1. Field of the Invention
The present invention relates to an ink jet recording head a method for preserving an ink container, or a recording head integrated with an ink container, and also to a mechanism for preventing ink leakage during an unrecording time or for preventing changes in pressure in an ink container on the whole as preferable uses.
The present invention relates to a recording head or a recording head integrated with an ink tank applicable to a printer, a copying machine, a facsimile, an ink jet recording apparatus to be used as business machines, and a method for preserving the recording head or the recording head integrated with an ink tank, or more particularly to a recording head detachable from the main apparatus.
2. Prior Art
In order to prevent clogging during the transportation or injection failure of an ink, an ink jet recording apparatus is usually provided with a capping device with an ink absorber so as to cover the discharge opening surface, as disclosed in Japanese Patent Application Kokai (Laid-open) No.59-198161. As a result of recent development of a cartridge-type ink jet head integrated with an ink tank, discharge opening surface protecting members without any capping device have been proposed to protect a discharge opening, for example, by providing a cap-like protective member having an ink absorber at the discharge opening, as disclosed in Japanese Patent Application Kokai (Laid-open) No.60-204348, or by using a sealing member based on vinylidene chloride resin as a protective tape for the discharge opening, as disclosed in Japanese Patent Application Kokai (Laid-open) No. 61-125851.
The present applicants proposed to cover the discharge section of a recording head integrated with an ink container and the atmosphere-communicating opening of the ink container section with a sealing tape using a specific adhesive, thereby bringing both of the discharge section and the atmosphere-communicating opening into a tightly closed structure. Ink leakage can be prevented thereby, and peeling of the sealing tape can be easily made when the ink head is used. The proposed covering with a sealing tape is quite practical and effective for preventing ink leakage.
However, the internal pressure in the ink cartridge is elevated due to rapid changes in the temperature of the surrounding circumstance during their transportation, because of the tight closing of the ink cartridge, and consequently ink leakage from other sealed parts is liable to occur. Thus, it is necessary to control elevation of ink tank internal pressure against changes in the surrounding circumstance.
Furthermore, the above-mentioned conventional capping device has such a fear that ink will leak due to vibrations during the normal transportation of printers to foul the printer inside. In case of the cartridge-type ink jet head integrated with an ink tank, the cap-like protective member is very expensive, or ink will fill the protective member to foul the discharge opening or cause clogging or discharge failure. Accordingly, sealing the discharge opening surface with a sealing tape has been studied. In case of the vinylidene chloride resin, the adhesive components have not been fully studied, and thus positioning of the tape to the discharge opening is quite difficult to make and also the workability is not good.
In case of using commercially available tapes from the viewpoint of cost and easy availability, the following disadvantages have been encountered and the commercially available can not be applied to the ink jet head.
The conventional adhesives can be classified into three main groups, i.e., 1) rubber-based adhesives, 2) silicone-based adhesives and 3) acrylic resin-based adhesives. The rubber-based adhesives 1) have a good adhesiveness, but have many unsaturated groups, which lead to chemical denaturing or deterioration. The silicone-based adhesives 2) have less denaturing and a good chemical resistance, but have a low adhesiveness. Tight bonding to articles cannot be obtained. The acrylic resin-based adhesives 3) have less denaturing, and require addition of an adhesive aid such as polyterpene resin, rosin, phenol resin, etc. and thus the peeling strength is high, and the adhesive aid resin dissolve into a water-soluble organic solvent contained in the ink. Furthermore, the acrylic resin of the ordinary acrylic resin-based adhesives contain oligomer components having a relatively low degree of polymerization, which gradually dissolve out to foul the discharge opening surface or the inside. These problems have been clarified by the applicants.
However, the present inventors encountered new problems which were not recognized in the above-mentioned propose. That is, during aircraft transportation there occurred peculiar cases of ink leakage at the positions sealed with the sealing tape due to considerable changes in internal pressure of the ink container or the entire recording head integrated with an ink container at a high temperature in the aircraft. When the adhesion strength of sealing is increased to prevent the ink leakage, tape peeling operation is correspondingly more difficult to make or ink leakage occurs at joints of the assembly of the recording head, or the strength of joints is lowered. These problems are more remarkable when the recording heads are produced at a lower cost to supply recording head at a more economical cost.